Ab initio study of the electronic structure of the molecule-based ferromagnet Co[N(CN)2]2

We have investigated the electronic and magnetic properties of the molecule-based magnet CoN(CN)₂]₂ using the full potential linearized augmented plane wave (FP-LAPW) method. The relative stability of the ground state, density of states and charge distributions were examined. Total energy calculations reveals that the ferromagnetic phase is a stable ground state for CoN(CN)₂]₂ in agreement with the previous experimental findings. It is noteworthy that we predict the CoN(CN)₂]₂ is a ferromagnetic semiconductor with a small band gap of 0.027 eV, and the semiconductor property can be connected to the strong crystal field splitting of Co²⁺ 3d states for CoN(CN)₂]₂. Such a molecule-based ferromagnetic semiconductor would offer a potential for semiconductor applications, therefore, an experimental confirmation of our theoretical predictions is encouraged.